No Arabic abstract
The ATLAS Forward Proton (AFP) detector is intended to measure protons scattered at small angles from the ATLAS interaction point. To this end, a combination of 3D Silicon pixel tracking modules and Quartz-Cherenkov time-of-flight (ToF) detectors is installed 210m away from the interaction point at both sides of ATLAS. Beam tests with an AFP prototype detector combining tracking and timing sub-detectors and a common readout have been performed at the CERN-SPS test-beam facility in November 2014 and September 2015 to complete the system integration and to study the detector performance. The successful tracking-timing integration was demonstrated. Good tracker hit efficiencies above 99.9% at a sensor tilt of 14{deg}, as foreseen for AFP, were observed. Spatial resolutions in the short pixel direction with 50 {mu}m pitch of 5.5 +/- 0.5 {mu}m per pixel plane and of 2.8 +/- 0.5 {mu}m for the full four-plane tracker at 14{deg} were found, largely surpassing the AFP requirement of 10 {mu}m. The timing detector showed also good hit efficiencies above 99%, and a full-system time resolution of 35 +/- 6 ps was found for the ToF prototype detector with two Quartz bars in-line (half the final AFP size) without dedicated optimisation, fulfilling the requirements for initial low-luminosity AFP runs.
LumiCal is a sampling electromagnetic calorimeter designed for the precise measurement of integrated luminosity in electron positron linear collider experiments. The present report contains a description and results of the first beam test of a multilayer LumiCal prototype with four silicon detector planes. A 5 GeV electron beam from the CERN PS T9 facility was used to study the performance of the LumiCal prototype. Presented results are mainly focused on the transverse structure of the observed electromagnetic shower and the Moli`ere radius measurement. A comparison with MC simulation is also discussed.
A novel scintillator detector, the SuperFGD, has been selected as the main neutrino target for an upgrade of the T2K experiment ND280 near detector. The detector design will allow nearly 4{pi} coverage for neutrino interactions at the near detector and will provide lower energy thresholds, significantly reducing systematic errors for the experiment. The SuperFGD is made of optically-isolated scintillator cubes of size 10x10x10 mm^3, providing the required spatial and energy resolution to reduce systematic uncertainties for future T2K runs. The SuperFGD for T2K will have close to two million cubes in a 1920x560x1840 mm^3 volume. A prototype made of 24x8x48 cubes was tested at a charged particle beamline at the CERN PS facility. The SuperFGD Prototype was instrumented with readout electronics similar to the future implementation for T2K. Results on electronics and detector response are reported in this paper, along with a discussion of the 3D reconstruction capabilities of this type of detector. Several physics analyses with the prototype data are also discussed, including a study of stopping protons.
Pixel detectors with cylindrical electrodes that penetrate the silicon substrate (so called 3D detectors) offer advantages over standard planar sensors in terms of radiation hardness, since the electrode distance is decoupled from the bulk thickness. In recent years significant progress has been made in the development of 3D sensors, which culminated in the sensor production for the ATLAS Insertable B-Layer (IBL) upgrade carried out at CNM (Barcelona, Spain) and FBK (Trento, Italy). Based on this success, the ATLAS Forward Physics (AFP) experiment has selected the 3D pixel sensor technology for the tracking detector. The AFP project presents a new challenge due to the need for a reduced dead area with respect to IBL, and the in-homogeneous nature of the radiation dose distribution in the sensor. Electrical characterization of the first AFP prototypes and beam test studies of 3D pixel devices irradiated non-uniformly are presented in this paper.
Results of beam tests with planar silicon pixel sensors aimed towards the ATLAS Insertable B-Layer and High Luminosity LHC (HL-LHC) upgrades are presented. Measurements include spatial resolution, charge collection performance and charge sharing between neighbouring cells as a function of track incidence angle for different bulk materials. Measurements of n-in-n pixel sensors are presented as a function of fluence for different irradiations. Furthermore p-type silicon sensors from several vendors with slightly differing layouts were tested. All tested sensors were connected by bump-bonding to the ATLAS Pixel read-out chip. We show that both n-type and p-type tested planar sensors are able to collect significant charge even after integrated fluences expected at HL-LHC.
A new small-diameter Monitored Drift Tube (sMDT) chamber has been developed for the muon spectrometer of the ATLAS experiment to handle the higher collision rates expected at the CERN High Luminosity Large Hadron Collider (HL-LHC). This paper presents measurements of the tracking resolution and hit efficiency of two prototype sMDT chambers constructed at the University of Michigan. Using cosmic-ray muons the sMDT tracking resolution of 103.7$pm8.1$ textmu m was measured for one chamber and 101.8$pm$7.8 textmu m for the other, compared with a design resolution of 106 textmu m. A further tracking resolution improvement to 83.4$pm$7.8 textmu m was obtained by using new high-gain readout electronics which will be added for HL-LHC. An average tracking efficiency of (98.5$pm$0.2)% was found for both chambers. The methodology used to determine the detector tracking resolution and efficiency, including reconstruction of sMDT data and a Geant4 simulation of the test chamber, is presented in detail.